The Color Purple

Today’s installment of Scientists You Should Know is brought to you by the color purple. Mauve, in fact. This past April marked 150 years since mankind stopped relying on plants and bugs to supply the colors of its world, and mauve was the first of those artificial colors. Before you snicker, consider that mauve was once such a novelty that an entire decade was named for it.* Before the discovery of purple dyes derived from coal tar, literally thousands of shellfish had to be slaughtered to obtain a few grams of purple – making it so expensive that it became a royal color in ancient times.

Until the advent of the artificial aniline colorants, most dyes were of plant (such as madder), insect (such as cochineal) or (I shit you not) bird fecal origin. Imagine the work it took to collect enough poop, bugs or plants to dye a garment, and you can see why a coal tar-derived synthetic dye was a huge leap forward – at least for the clothing manufacturers, if not for the insect-gatherers. We’ll leave the birds right out of it, because I’m quite sure even the people who made their living from that extraction were happy to learn a new skill or two.

The dominion of plant and animal dyes came to an end over the Easter academic break in 1856, when an 18 year old student of the Royal College of Chemistry, working in his home laboratory, was trying to make quinine from coal tar, which was a common, oily by-product of the process of making coke and town gas from coal. The project had been suggested to William Perkin by his mentor, the German organic chemist August Hofmann.

At the time (the 1840’s) there were few organic chemists of note in Great Britain, and August Wilhelm von Hofmann (1818-1892), who had worked under Liebig, was imported to London from Germany. For an assistant, some years later, Hofmann drew a teen-age assistant, William Henry Perkin (1838-1907). One day, in Perkin’s presence, Hofmann speculated aloud on the feasibility of synthesizing quinine, the valuable anti-malarial. Hofmann had done research on chemicals obtained from coal tar (a thick, black liquid obtained by heating coal in the absence of air), and he wondered whether it was possible to synthesize quinine from a coal tar chemical like aniline. The synthesis, if it could be accomplished, would be a great stroke, he said: it would relieve Europe’s dependence on the far-off tropics for the supply of quinine.

Perkin’s story has an awful lot of examples where one might remark on what David Foster calls meta-skills, and I see two of them packed into that little paragraph. First is the skill of knowing when to go ahead and make a decision based on limited information. It is an especial weakness of academics to exhibit analysis paralysis, where decisions are deferred indefinitely in favor of an infinite quest for better data. That would have been a mistake, in this case:

Had he or Hofmann known more of the structure of the quinine molecule, they would have known the task was impossible to mid-nineteenth century techniques. Fortunately, Perkin was blissfully ignorant of this and, though he failed, he achieved something perhaps greater.

David Foster had a post on this a while back at the Photon Courier. Sometimes, having a little more information does not really help in decision making, because the totality of information needed to make a really good decision is so far beyond the knowledge capabilities of the present that waiting for a few more tidbits will not make a decision any better, and, given the potential for mis-interpretation, a small amount of new information may actually make the decision worse at least some of the time.

We in Industry run a fine line all the time between over-directing the efforts of our creatives and letting them run wild. A creative running wild tends not to get much useful done in the medium term (when the financials come home to roost), but one on too short a leash gets nothing done before he or she up and quits on you. One rule of thumb helps, in this regard, though – you can’t steer a ship that isn’t moving. By steering the ship towards quinine, Perkin prepared his mind to test reactions and find new substances, and chance favors the prepared mind. It certainly favored Perkin’s.

The other meta-skill I see exhibited is the ability to recognize one’s own talent and run with it. Unfortunately, this thwarted by the educational system that has sprung up in the industrial age. We waste an awful lot of years of prime talent in our current educational system. I’m planning to do another post soon on education, so I won’t beat this to death, but I will say that Perkin enrolled in the college of Chemistry at the age of fifteen. That is extremely difficult to do in today’s cookie-cutter academic world, but I would submit that the ability to enroll in AP classes is de facto evidence that more than a few years of primary education could be shaved off for the best students, to the economic benefit of all (not to mention the quality of life benefits). Perkin got to retire at 36, one year younger than I am now.

Now back to our story. In 1856 Perkin recognized that the pretty purple compound sitting in his retort that Easter** might be useful as a dye. So he sent it off to a dyer:

Perkin sent samples of his colorant to Pullars of Perth, dyers of piece goods with connections throughout Europe, who reported favorably of the novel substance. Purple was a popular color, but the alternatives, made from lichens and the guano-derived murexide, were not fast to light, especially in the acidic atmospheres of industrial cities.

Perkin’s purple dye, later named mauveine, had several advantages: it was cheap and easy to produce from a nearly worthless byproduct of a common process, it did not fade in light, it resisted multiple washings, and I suspect that it also looked to be a similar color under gaslight (the common night-time illumination for entertainments of the class of people who would wear silk garments) as it did in sunlight – that was certainly a draw for the green dye that Hoechst came up with a few years later.

With all those advantages, Perkin’s father, a successful building contractor, bankrolled his dye venture. Hofmann, of course, was aghast, warning Perkin not to leave the life philosophical for the life practical.William didn’t listen.

Perkin immediately ran into a wall, though.

Unfortunately, the product proved difficult to sell, except for the limited application of dyeing silk, because of the difficulties of attachment to cotton. Consequently, there was little enthusiasm from the calico printers in Lancashire and Scotland.

Nevertheless, purple had become the leading color of fashion in Paris and London, probably because of the introduction of a fast and brilliant lichen dye, French purple, manufactured by a firm in Lyon.

While the dye worked wonders on silk, it didn’t stick to cotton due to the significantly different chemical structures of those fibers. But, there were already known techniques to get around that little problem for natural dyes. The solution is called a mordant (think of a mordant as a chemical snap-link that attaches a loop on to the dye to a loop on the fiber). One of Perkin’s first post-mauvine technical successes was to develop a mauveine mordant for cotton in 1859, and he was off to the races, competing favorably with the lichen-based dye. At this point, the French floral name mauve was also attached to the color, displacing Perkin’s original, classical-derived name of Tyrolean Purple.

Looking at this whole episode from the lens of Porter’s Five Forces, the major substitute was so economically disadvantaged (gathering the lichen, extracting the colorant, and working it up took so many more resources than a couple of chemical reactions with a coal-tar distillate) that Perkin achieved a virtual monopoly.

There is another illustration of a meta-skill lurking here, though: knowing how to put the right people and the right mindset to work on a problem. Academics and industrial scientists have a different mindset for a reason: academics have the primary responsibility of publishing, industrial scientists have the primary responsibility of creating or improving a product on a finite timescale. It is always a mistake to underestimate the time it will take a discovery to move from lab curiosity into the real of manufactured products. It took Perkin nearly 3 years to develop the technology to go after the huge calico market. Underestimating the importance of the scale-up step is the major fallacy in the thinking behind SBIRs. I wrote a piece on SBIRs a while back, and I know of plenty of academics who would take a discovery such as mauveine, slap together a company, and waste hundreds of thousands of taxpayer dollars on looking at the structure / color relationship of analogs of the parent molecule, rather than trying to find a mordant and make a product. This is why so few SBIR-receiving entities become economically self-sufficient. Academics do not like doing the boring and repetitive (not to mention un-publishable) sets of experiments required for industrialization, which is why I think that they should not become involved in technology transfer of their ideas unless they are willing to forego their academic work, at least temporarily. Perkin was willing to give up the life of the don, although he longed to return to matters philosophical. More on that below.

Perkin continued to build on his mauveine success, discovering other colors, Britannia Violet and Perkin’s Green. He also spent an awful lot of time on what we today would call chemical engineering. At the height of his company’s success in the 1860s, Perkin and his brother Thomas were designing state of the art chemical manufacturing plants:

Perkin’s principal contribution was in the design and manufacture of suitable process equipment, a considerable feat of chemical engineering based almost entirely on empirical studies. His work formed the basis of subsequent improvements carried out once knowledge about the chemical reactions became available during the 1870s. Fortunately, Perkin left a comprehensive record of the development of his alizarin manufacture from 1869 to the end of 1873, published in 1879, and complemented with information in his Hofmann Memorial Lecture, published in 1896. His processes made possible dye-manufacture on a high tonnage scale, and encouraged moves towards unit operations. This became critical to the continued growth of the dye and, later, organic chemical industries.

There was trouble brewing for the British dye industry by the mid-1860s, however. Hofmann found much better reception for his talents back in Germany, and re-patriated in 1864 or 5 (my sources disagree). Kekule had proposed the (correct) structure for benzene and other organic molecules by this time, so the Germans were poised to rationally discover new compounds, as opposed to relying on the trial-and-error process that had produced mauveine:

It was not long after Perkin’s original feat that Kekule and his structural formulas supplied organic chemists with a map of the territory, so to speak. Using that map, they could work out logical schemes of reactions, reasonable methods for altering a structural formula bit by bit in order to convert one molecule into another. It became possible to synthesize new organic chemicals not by accident, as in Perkin’s triumph, but with deliberation.

The advantage gained by the symbiosis of theory and a large population of technically educated citizens led the Germans to eventually outpace the British, which was first signaled by the fact that BASF beat Perkin to the patenting of the bright red alizarin dye by a single day in 1869. Perkin retained the right to manufacture and sell in the UK, but the German firm took the Continent and North America.

Perkin’s discovery gave chemistry a huge boost in England, which the English system of higher education utterly failed to exploit. The German colorists, finding themselves more valued at home, returned to Germany to found the German dye giants cum pharmaceutical, film and polymer behemoths that we know today as BASF, Hoechst, AGFA, and Bayer, among others. Sure, many of the “British” organic chemists in the Royal College were Germans, but if they had been encouraged to stay in Britain train an entire generation of Perkin clones, history (including WWI) might have looked very different in the 20th century. (BTW, WWI British soldiers went to battle in uniforms colored with German khaki dye, and the absurd red trousers of the circa 1914 French army owed their color to German dyes as well).

The meta-skill I think was exhibited by the Germans here is the ability to tinker with one’s own cultural assumptions. This often leads to competitive advantage. If Britain had not been in the grip of a class-oriented worldview, chemistry might have taken much firmer root there before WWI. (WWI forced the issue and saw a resurgence of the British dye industry with the formation of the companies that eventually merged into ICI). Respect for practical education and the egalitarian development of talent from all walks of life (and in the ultra-modern world, from both sexes) are essential for competitiveness. The British social system of the 1870s and 80s, sneering at their engineers and requiring useless dead languages known mostly to the upper classes in order to participate in higher education (see my post on Kolthoff on how this same phenomenon at Utrecht almost derailed the career of that great chemist), was a huge albatross – and this ushered in the only period in modern history where the Germans arguably outdid the Anglosphere for reasons of culture*** – the scientific flowering from about 1870 to roughly the 1927 Solvay Congress.

A quote from James Burke’s original companion volume to the BBC series Connections might help me make my point:

Besides, the industrial scientist and engineer enjoyed a relatively low social position and perhaps because of this , like Perkin, they felt some embarrassment at making money. Like Perkin, they dreamed of the day that they could afford to return from industry to ‘pure science’.

The German attitude was entirely different. The influence of the great German philosophers of the eighteenth century, among them Kant and Wolff, and the pedagogic teachings of the Swiss Pestalozzi helped to radically alter the structure of German education. These men believed that the body of man’s knowledge was incomplete, and that the work of higher education was not to inculcate the repetition of known fact, but to train minds in the business of investigation. In the early nineteenth century, the Germans founded technical high schools, and by the 1880s the standardization of university and technical school training mixed the social classes in a way that would not have been acceptable to the English. The new German dyestuffs industry had only to go to the schools to find the talent on which to build.

The gulf between the pure and the applied sciences was probably as narrow as it has ever been in fin de siecle Germany. As a product of the German school system, even that consummate theoretician Albert Einstein invented something practical.

There was another reason that the British industry failed: lack of investment capital. James Burke again:

One of the reasons that Britain let slip its early lead in the industry was that the country was rich. It had a stronger industrial base than the rest of Europe, and benefited from cheap imports from the colonies that also acted as captive markets for British manufacturing. It was too easy for money to be made in areas that were already tried and known to be sound. No banker would risk money on a new venture such as dyes when he did not need to.

With the rise of the German dye industry came the decline of the British one, and Perkin sold his company in 1874. He “retired” to academic research, and three synthetic organic reactions were discovered by and are named for him: the Perkin Reaction, the Perkin Rearrangement, and the Perkin Alicyclic Synthesis . In addition, one of the premier Organic Journals was named for him: the Perkin Transactions (now published under the more prosaic and ungrateful title Organic and Biomolecular Chemistry). In the course of discovering the Perkin Reaction, he synthesized coumarin, the first synthetic perfume.

In a completely unanticipated consequence, the wide availability of synthetic dyes allowed biologists such as Paul Ehrlich to try staining micro-organisms with derivatives of mauveine. Ehrlich discovered the dye that first facilitated the detection of TB. As a direct result of this research, one of Ehrlich’s assistants, Sachihiro Hata, discovered the first anti-syphilitic, Salvarsan, in 1908. In more indirect ways German scientists discovered pesticides, drugs, plastics, and explosives while working on novel dyes.

In 1906, on the 50th anniversary of his discovery, the Society of Dyers and Colourists established the Perkin Medal. It’s not awarded every year, but it was this year, to commemorate mauvine’s 150th anniversary.

The SDC chose the occasion to award its Perkin Medal, a supremely rare and valuable accolade (solid gold, and as big as a drink coaster), for the first time this century. Not one but three recipients—Ichiro Endo of Canon, Minoru Usui of Seiko Epson, and John Vaught of Hewlett-Packard—shared the spotlight for their roles in inventing inkjet and thermal color printing.

The American Section of the Society of Chemistry and Industry also awards a Perkin Medal, and although it isn’t a big hunk of gold, it is awarded every year. Perkin himself was its first recipient in 1906.

Perkin died in 1907, of appendicitis.

There is one more what I might perhaps call a meta-lesson in all of this. Mauve was one of those levers that open up the rest of society’s pocket book to funding avenues of inquiry with tremendous downstream consequences that no one – especially the inventors and discoverers – foresaw. History is rife with this examples of this, yet still the socialists and economic planners think that the mechanism is of no consequence and can be simulated by human decision making. Most readers of this site probably believe that Hayek demolished that theory, but never underestimate the longevity of a stupid idea, or people’s willingness to believe in simple falsehoods, to the exclusion of complex truths.

Long-term planning rarely works, in science or in economics. Socialists (and academics) also tend to also sneer at small advances in technology, forgetting how each piece fits into the whole of human progress. New ideas are risky, and often need a champion all too often lacking in bureaucratic planning departments – or even in capitalistic British banks. There were plenty of plant, bug, and guano-derived dyes before mauveine. Who needed another dye? A dye is a silly, bourgeois thing to invest your scientific talent on. A Soviet-style science planner most likely would have continued the quest for quinine, and gradually watched organic chemistry wane in importance as nothing came of the quest (and useful compounds sat on the shelf). If Perkin had insisted on ignoring the dye and continuing the quest for quinine, much less money and effort would have flowed into organic chemistry, and the development of the modern material world would have been delayed.

From mauveine’s humble beginning come the plastics in your computer, your car (that allows it to be both safer and to get so much better gas mileage than even the econoboxes of the 70s), the bottle your soft drink came in, your contact lenses, and even (if you are unlucky enough to have a CV disease) the stents that keep your blood flowing, all come from the industry founded on purple. Not just plastics, but much of the invisible materials that sustain the modern world: the synthetic fertilizers that support the world’s current population, every synthetic drug, latex paints, perfumes, cleaning agents, many disinfectants, anti-dandruff agents in your shampoo, the shampoo itself, the explosives used to mine the gold in your wedding ring – all find their historical roots in the color purple.

* That was just when the color hit America a decade and a half after raging in Europe – the original mauve decade was the 1860s on the Continent and in the UK.

** Perhaps this is the origin of the workaholic expectations in graduate school so ably noted by Derek Lowe:

Ah, those holidays. I still have in my files a memo from my old chemistry department, reminding everyone that the university (undergraduate) vacation schedule most definitely did not apply to us. Do not attempt to take these holidays was the very pointed message, because we will notice if you do. I sure didn’t. I did take off some time at Thanksgiving and Christmas, and I didn’t work every single July 4th, but otherwise it was a rare, rare day when I wasn’t in the lab.

*** I will point out that two of the nastier aspects of German culture eventually undid this head start in physics and chemistry, and the more egalitarian elements of the Anglosphere retook the lead in the physical sciences with a vengeance after those counterproductive aspects of German society reared their ugly heads. The first was the German over-fondness of order (“profitable obedience”, in the words of Dame West) that lead to the Herr Professor Doctor ossification in academia that I blogged about here in reference to its export to the former USSR. That killed off innovation in all but the narrowest set of fields in any given institution, because of the pyramidal nature of the scientific hierarchy (as opposed to the American system where a University rarely has more than two or three principle investigators working on the same type of research, an usually not even that many). The other was a spike in Germany’s traditional anti-semitism that culminated in the emigration of Einstein et al – if you want to build a society based on technical merit, the last thing you want to do is exclude Jews from higher education. In an ugly and ironic twist on this theme, the largest of the German dyestuff firms that grew out of Perkin’s and Hofmann’s investigations merged into I.G. Farben under the Nazis, which was broken back into its constituent firms as a punishment for Farben’s use of Jewish slave labor and its manufacture of Zyklon B.